U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights

A New Mechanism for Microbial Community Metabolism
Published: December 06, 2010
Posted: January 11, 2011

Outside of laboratories, microbial species rarely exist in isolation. Many important environmental processes are actually mediated by complex communities of microbes. In many cases, two or more species have evolved to perform a cooperative metabolic activity that would be energetically unfavorable for either organism acting independently. Research published in the December 3 issue of Science and led by DOE scientist Derek Lovley of the University of Massachusetts, Amherst, describes a new mechanism by which the bacterium Geobacter metallireducens consumes ethanol, an important intermediate compound in oxygen free soils and sediments, in cooperation with a second organism Geobacter sulfureducens. For this reaction to yield energy for either partner, electrons produced from ethanol oxidation must be rapidly consumed. Although it was previously assumed that the first organism uses a hydrogen production mechanism to pass electrons to its partner, the authors have discovered that electrons are instead directly fed to G. sulfureducens via conductive "nanowires" called pili on the cell surface, resulting in much more efficient collaborative growth. These results provide important new clues on the fundamentals used by microbes to mediate important environmental processes such as carbon cycling and contaminant transformation and suggest intriguing new approaches to direct generation of electricity in microbial fuel cell systems.

Reference: Summers, Z.M., H. E. Fogarty, C. Leang, A. E. Franks, N. S. Malvankar, and D. R. Lovley. 2010. "Direct Electron Exchange Within Aggregates of an Evolved Syntrophic Coculture of Anaerobic Bacteria," Science 330:1413-15.

Contact: Dan Drell, SC-23.2, (301) 903-4742
Topic Areas:

  • Research Area: Subsurface Biogeochemical Research
  • Research Area: Microbes and Communities
  • Research Area: Sustainable Biofuels and Bioproducts

Division: SC-23.2 Biological Systems Science Division, BER


BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Aug 24, 2019
New Approach for Studying How Microbes Influence Their Environment
A diverse group of scientists suggests a common framework and targeting of known microbial processes [more...]

Aug 08, 2019
Nutrient-Hungry Peatland Microbes Reduce Carbon Loss Under Warmer Conditions
Enzyme production in peatlands reduces carbon lost to respiration under future high temperatures. [more...]

Aug 05, 2019
Amazon Forest Response to CO2 Fertilization Dependent on Plant Phosphorus Acquisition
AmazonFACE Model Intercomparison. The Science Plant growth is dependent on the availabi [more...]

Jul 29, 2019
A Slippery Slope: Soil Carbon Destabilization
Carbon gain or loss depends on the balance between competing biological, chemical, and physical reac [more...]

Jul 15, 2019
Field Evaluation of Gas Analyzers for Measuring Ecosystem Fluxes
How gas analyzer type and correction method impact measured fluxes. The Science A side- [more...]

List all highlights (possible long download time)